There is little published literature to support the claim that a successful total knee replacement (TKR) is predictive of future good outcomes on the contralateral side. The objective was to identify whether outcome from the first of staged TKRs could be used to predict the outcome of the contralateral TKR. This was a retrospective cohort study of 1687 patients over a 25-year period undergoing staged bilateral TKRs in a UK arthroplasty centre. A control group of 1687 patients undergoing unilateral TKR with matched characteristics was identified. Primary outcomes were satisfaction and Knee Society Score (KSS) at one year. Preoperative status was comparable for pain, ROM and KSS (mean 41, 45, 43±14). At one year follow up, dissatisfaction was similar for all groups (4% first of staged TKR, 4% second of staged TKR, 5% controls). If the first TKR had a good outcome, the relative risk of a contralateral bad outcome was 20% less than controls (95% CI 0.6–1.2). If the first TKR had a poor outcome, the risk of a second poor outcome was 4 times higher (95% CI 2.8–6.1), increasing from 6% to 27% (absolute risk). Patients undergoing the second of staged TKRs with a previous good outcome are likely to do well in their second procedure (94 in 100 will go on to have a second good outcome). Of those with a previous poor outcome, 27 in 100 will have a second poor outcome. The trend was persistent despite correcting for gender, age, BMI, and diagnosis

We aimed to determine the rate of and risk factors for post-traumatic osteoarthritis (PTOA) and total knee arthroplasty (TKA) requirement after operative management of tibial plateau fractures (TPF) in older adults. We conducted a retrospective cohort study of 182 operatively managed TPFs in 180 patients ≥60 years old over a 12-year period with minimum follow up 1 year. Data including patient demographics, clinical frailty scores, mechanism of injury, management, reoperation and mortality were recorded. Radiographs were reviewed for: Schatzker classification; pre-existing knee osteoarthritis (KOA); severe joint depression >15mm; and development of PTOA. Kaplan Meier survival analysis was performed. Regression analysis was used to identify risk factors for radiographic indication for TKA and actual TKA. Forty-seven percent were Schatzker II fractures. Radiographic KOA was present at fracture in 32.6%. Fracture fixation was performed in 95.6% cases and acute TKA in 4.4%. Thirteen patients underwent late TKA (7.5%). At five-years, 11.8% (6.0-16.7 95% CI) had required TKA and 20.9% (14.4-27.4 95% CI) had a radiographic indication for TKA. Severe joint depression and pre-existing KOA were associated with worse survival for endpoints radiographic indication for TKA and actual TKA. Severe joint depression (HR 2.49(1.35-4.61 95% CI), p=0.004), pre-existing KOA (HR 2.23(1.17-4.23), p=0.015) and inflammatory arthropathy (HR 2.4(1.04-5.53), p=0.039) were independently associated with radiographic indication for TKA. In conclusion, severe joint depression and pre-existing arthritis are independent risk factors for both severe PTOA and TKA after TPFs in older adults. These features should be considered as an indication for primary management with acute TKA

Unicompartmental knee osteoarthritis can be treated with either Total Knee Arthroplasty (TKA) or Unicompartmental Knee Arthroplasty (UKA) and controversy remains as to which treatment is best. UKA has been reported to offer a variety of advantages, however many still see it as a temporary procedure with higher revision rates. We aimed to clarify the role of UKA and evaluate the long-term and revision outcomes. We retrospectively reviewed the pain, function and total Knee Society Score (KSS) for 602 UKA and 602 TKA in age and gender matched patients over ten years. The total pre-operative KSS scores were not significantly different between UKA and TKA (42.67 vs 40.54 P=0.021). KSS (pain) was significantly better in the TKA group (44.39 vs 41.38 P= 0.007) at one year and at five years post-operatively (45.33 vs 43.12 P=0.004). There was no statistically significant difference for KSS (total) in TKA and UKA during the study period. 16.3% of UKA and 20.1% of TKA had a documented complication. 79 UKA (13%) and 36 TKA (6%) required revision surgery. Despite the higher revision rate, pre-operative KSS (total) before revision was not significantly different between UKA and TKA (42.94 vs 42.43 P=0.84). Performance for UKAs was inferior to TKAs in Kaplan-Meier cumulative survival analysis at 10 years (P<0.001). Both UKA and TKA are viable treatment options for unicompartmental knee osteoarthritis, each with their own merits. UKA is associated with fewer complications whereas TKA provides better initial pain relief and is more durable and less likely to require revision

We aim to determine the differences in lower limb joint kinematics during the golf swing of patients who had undergone Total Knee Arthroplasty (TKA) and a control group of native knee golfers. A case-control study was undertaken with ten golfers who had undergone TKA (cruciate retaining single radius implant) and five age and matched golfers with native knees. Each golfer performed five swings with a driver whilst being recorded at 200Hz by a ten-camera motion capture system. Knee and hip three-dimensional joint angles (JA) and joint angular velocities (JAV) were calculated and statistically compared between the groups at six swing events. The only significant differences in knee joint kinematics between TKA and control groups was a lower external rotation JA in the left knee during the backswing (p=0.010). There was no significant difference in knee JAV between the groups. Both hips demonstrated significantly (p=0.023 for left and p=0.037 for right) lower flexion in the TKA group during the takeaway swing event, and there was lower internal rotation in the backswing and greater external rotation in the downswing of the right hip. There was also slower left hip extension JAV in the downswing. Normal knee kinematics were observed during the golf swing following TKA, with the exception of reduced external rotation in the left knee during the back swing and the right during the down swing. The differences demonstrated in the hip motion indicate that they may make compensatory movements to adjust to the reduced external rotation demonstrated in the knee

Restoration of native Coronal Plane Alignment of the Knee (CPAK) phenotype is a strategy suggested to achieve better satisfaction. The aim of this study was to investigate the influence of changes in CPAK classification on patient-reported outcome measures (PROMs) and survivorship in a large cohort of manual mechanically aligned (MA) cemented TKAs. A retrospective analysis of 1062 consecutive cemented TKAs using MA philosophy at a single institution. Pre- and post-operative hip-knee-ankle radiographs were classified using the CPAK classification. Oxford Knee Score (OKS) and patient satisfaction (4-point-Likert scale) were collected prospectively. Implant survival data was obtained from our national arthroplasty database. We compared the outcomes of patients who maintained or changed their CPAK classification following TKA. Satisfaction was analysed using chi-square test, and OKS was analysed using Mann-Whitney test. Pre-operatively, most patients were CPAK type-I (38.8%). 85.5% of patients changed their CPAK type post-operatively, with CPAK type-V observed in 41.2% of these. Significantly better satisfaction (p=0.033) and OKS (p=0.021) were observed at one-year follow-up in patients who changed CPAK type, although the difference was below OKS minimally important clinical difference. There was no difference in satisfaction (p=0.73) and OKS (p=0.26) at one year between CPAK-V and non-V classifications. Post-operative CPAK type had no correlation with satisfaction and OKS. 12 TKAs (1.1%) were revised within 10 years (3 septic). In this large cohort of MA-TKA, excellent survivorship was observed at 10 years, with no demonstrable difference in outcome related to the final CPAK phenotype or change in phenotype

There is a lack of evidence surrounding selective patella resurfacing, but patella cartilage loss at time of total knee arthroplasty (TKA) is often used as an indication in those who perform it. This study compares the outcomes of TKA without patella resurfacing in patients with and without patella cartilage loss (PFOA). Prospective case control study of 209 consecutive patients undergoing cruciate retaining single radius TKA without patella resurfacing for KL≥3 osteoarthritis. The presence and location of full thickness patella cartilage loss was documented intra-operatively at TKA, identifying n=108 cases with PFOA (mean age 70±9.7, mean BMI 31±6.2, 72 (67%) female) Vs n=101 controls without PFOA (age 68±9.2, BMI31±5.6, 52 (51%) female). Primary outcome measure was improvement in the Oxford Knee Score (OKS) at one year. There were more females in the PFOA group (67% Vs 51%, p=0.037), but no other preoperative differences. There was no difference in preoperative OKS between patients with patella cartilage loss (20.6±7.9) and those without (21.0±7.2, p=0.720). There was no difference in OKS improvement following TKA without patella resurfacing between those with full thickness patella cartilage loss (14.2±9.8) and those without (15.4±9.5, p=0.365). Facet involvement (number and location) did not affect OKSs. No differences were found in the individual OKS questions between groups (p>0.05). There was no difference in one-year OKS or improvements therein between patients with and without full thickness patella cartilage loss treated with single radius cruciate retaining TKA without patella resurfacing, questioning its use an indication for selective patella resurfacing

Radiological evidence of post-traumatic osteoarthritis (PTOA) after fracture of the tibial plateau is common but end-stage arthritis which requires total knee arthroplasty is much rarer. The aim of this study was to examine the indications for, and outcomes of, total knee arthroplasty after fracture of the tibial plateau and to compare this with an age and gender-matched cohort of TKAs carried out for primary osteoarthritis. Between 1997 and 2011, 31 consecutive patients (23 women, eight men) with a mean age of 65 years (40 to 89) underwent TKA at a mean of 24 months (2 to 124) after a fracture of the tibial plateau. Of these, 24 had undergone ORIF and seven had been treated non-operatively. Patients were assessed pre-operatively and at 6, 12 and > 60 months using the Short Form-12, Oxford Knee Score and a patient satisfaction score. Patients with instability or nonunion needed total knee arthroplasty earlier (14 and 13.3 months post-injury) than those with intra-articular malunion (50 months, p < 0.001). Primary cruciate-retaining implants were used in 27 (87%) patients. Complication rates were higher in the PTOA cohort and included wound complications (13% vs 1% p = 0.014) and persistent stiffness (10% vs 0%, p = 0.014). Two (6%) PTOA patients required revision total knee arthroplasty at 57 and 114 months. The mean Oxford knee score was worse pre-operatively in the cohort with primary osteoarthritis (18 vs 30, p < 0.001) but there were no significant differences in post-operative Oxford knee score or patient satisfaction (primary osteoarthritis 86%, PTOA 78%, p = 0.437). Total knee arthroplasty undertaken after fracture of the tibial plateau has a higher rate of complications than that undertaken for primary osteoarthritis, but patient-reported outcomes and satisfaction are comparable. Cite this article: Bone Joint J 2015;97-B:532–8

The objective of this study was to compare differences in alignment following robotic arm-assisted bi-unicompartmental knee arthroplasty (Bi-UKA) and conventional total knee arthroplasty (TKA). This was a prospective, randomised controlled trial of 70 patients. 39 TKAs were implanted manually, as per standard protocol at our institution, and 31 Bi-UKA patients simultaneously received fixed-bearing medial and lateral UKAs, implanted using robotic arm-assistance. Preoperative and 3-month postoperative CT scans were analysed to determine hip knee ankle angle (HKAA), medial distal femoral angle (MDFA), and medial proximal tibial angle (MPTA). Analysis was repeated for 10 patients by a second rater to validate measurement reliability by calculating the intra-class correlation coefficient (ICC). Mean change in HKAA towards neutral was 2.7° in TKA patients and 2.3° in Bi-UKA patients (P=0.6). Mean change in MDFA was 2.5° for TKA and 1.0° for Bi-UKA (P<0.01). Mean change in MPTA was 3.7° for TKA and 0.8° for Bi-UKA (P<0.01). Mean postoperative MDFA and MPTA for TKAs were 89.8° and 89.6° respectively, indicating orientation of femoral and tibial components perpendicular to the mechanical axis. Mean postoperative MDFA and MPTA for Bi-UKAs were 91.0° and 86.9° respectively, indicating a more oblique joint line orientation. Inter-rater agreement was excellent (ICC>0.99). Early functional activities, according to the new Knee Society Scoring System, favoured Bi-UKAs (P<0.05). Robotic arm-assisted, cruciate-sparing Bi-UKA better maintains the natural anatomy of the knee in the coronal plane and may therefore preserve normal joint kinematics, compared to a mechanically aligned TKA. This has been achieved without significantly altering overall HKAA

We report on the 5 year results of a randomized study comparing TKR performed using conventional instrumentation versus electromagnetic computer-assisted surgery. This study analysed patient reported outcome measures (PROMs) at 5 years utilising the American Knee Society Score (AKSS), Oxford Knee Score (OKS), the Short Form 36 score and range of motion (ROM). Of the 200 patients enrolled 125 completed 5 year follow up, 62 in the navigated group and 63 in the conventional group. There were 28 deceased patients, 29 withdrawals and 16 lost to follow-up. There was improvement in clinical function in most PROMs from 1-5 year follow up across both groups. OKS improved from a mean of 26.6 (12–55) to 35.1 (5–48). AKSS increased from 75.3 (0–100) to 78.4 (−10–100), SF36 from 58.9 (2.5–100) to 53.2 (0–100). ROM improved by an average 7 degrees from 110 degrees to 117 degrees (80–135). There was no statistically significant difference in PROMs between the groups at 5 years. Patients undergoing revision surgery were identified from the dataset and global PACS. There were no revisions within 5 years in the navigated group and 3 revisions in the conventional group, two for infection and one for mid-flexion instability, giving an all cause revision rate of 3.06% at 5 years for this group. There appears to be no significant advantage in clinical function for patients undergoing TKR for OA of the knee with electromagnetic navigation when compared to conventional techniques. There may be an advantage in reducing early revision rates using this technology

The primary aim of this study was to compare the knee specific functional outcome of partial compared with total knee replacement (TKR) for the management of patellofemoral osteoarthritis. Fifty-four consecutive Avon patellofemoral replacements were identified and propensity score matched to a group of 54 patients undergoing a TKR with patella resurfacing for patellofemoral osteoarthritis. The Oxford knee score (OKS), the Short Form (SF-) 12 and patient satisfaction were collected (mean follow up 9.2 years). Survival was defined by revision or intention to revise. There was no significant difference in the OKS (p>0.60) or SF-12 (p>0.28) between the groups. The TKR group was significantly less likely to be satisfied with their knee (95.1% versus 78.3%, OR 0.18, p=0.03). Length of stay was significantly (p=0.008) shorter for the Avon group (difference 1.8 days, 95% CI 0.4 to 3.2). The 10 year survival for the Avon group was 92.3% (95% CI 87.1 to 97.5) and for the TKR group was 100% (95% CI 93.8 to 100). There was no statistical difference in the survival rate (Log Rank p=0.10). The Avon patellofemoral replacement have a shorter length of stay with a functional outcome and satisfaction rate that is equal to that of TKR. The benefits of the Avon need to be balanced against the increased rate of revision when compared with TKR

Background. Improving quality and efficiency is a priority in health policy. Several studies have shown a correlation between high hospital volume and improved results of surgery. In Norway, orthopaedic surgeons operate a relatively low number of total knee replacements compared with other countries. The number of total knee replacements has, however, increased significantly over the past 10 years. Some studies have also shown an association between surgeon volume and outcomes after total knee arthroplasty (TKA). Purpose. We wanted to study a possible correlation between prosthesis survival and surgery volume of TKA, both with respect to hospital volume and surgeon volume. Materials and Methods. To examine the annual surgery volume per hospital we used registry data from the Norwegian Arthroplasty Register (NAR) for cemented TKA without patella component from 1994–2009. A questionnaire regarding surgeon volume in 2000 and 2009 was sent to all 58 operating hospitals in Norway, as this is not registered in the NAR. We received responses from 29 hospitals. Surgeon volume was defined by the percentage of surgeons at the hospital who operated 1–10 TKA over a year. Cox regression (without adjustment) was used to estimate proportions without revision and relative differences (RR). Analyses were also done for a subset of commonly used prostheses (AGC, LCS, LCS Complete, Duracon, NexGen, Profix), and for the prosthesis LCS and Profix separately. Results. Median annual hospital volume increased from 19 knees in 1995 to 83 in 2009. Prosthesis survival at 10 years was 92.5% (95% CI: 91.6–93.4) with 1–24 operations annually and 95.3% (93.7–96.8) with 100–149 operations. We found a lower risk of revision for hospitals with 25–49 (RR = 0.86, p = 0.06), 50–99 (RR = 0.81, p = 0.01, 100–149 (RR = 0.59, p<0.001 and 150 or more (RR = 0.48, p <.001) operations per year, compared to the hospitals with 1–24 operations. The analyses for subgroups of prosthesis brands provided similar results, except for the Profix prosthesis where there was no difference between hospital volumes. In 2000, 47% of the Norwegian hospitals had two thirds of the surgeons operating 1–10 TKA annually, but this was reduced to 24% in 2009. High annual surgeon volume gave the best results in our analyses. Conclusion. There has been an increase in the number of TKAs over time, in Norway as in other countries. Surgeon volume has also increased over time. Previously a high number of surgeons performed a low number of total knee arthroplasties, but this has been significantly reduced over the last 10 years. Survival curves from the NAR show a gradual improvement over time regarding the results of TKA. Our study indicated better results for TKA both at higher hospital volume and surgeon volume. Further analyses should investigate whether other factors may have an influence on this result

Anterior knee pain (AKP) is the commonest complication of total knee arthroplasty (TKA). This study aims to assess whether sagittal femoral component position is an independent predictor of AKP after cruciate retaining single radius TKA without primary patellofemoral resurfacing. From a prospective cohort of 297 consecutive TKAs, 73 (25%) patients reported AKP and 89 (30%) reported no pain at 10 years. Patients were assessed pre-operatively and at 1, 5 and 10 years using the short form 12 and Oxford Knee Score (OKS). Variables assessed included demographic data, indication, reoperation, patella resurfacing, and radiographic criteria. Patients with AKP (mean age 67.0 (38–82), 48 (66%) female) had mean Visual Analogue Scale (VAS) Pain scores of 34.3 (range 5–100). VAS scores were 0 in patients with no pain (mean age 66.5 (41–82), 60 (67%) female). Femoral component flexion (FCF), anterior femoral offset ratio, and medial proximal tibial angle all differed significantly between patients with AKP and no pain (p<0.001), p=0.007, p=0.009, respectively). All PROMs were worse in the AKP group at 10 years (p<0.05). OKSs were worse from 1 year (p<0.05). Multivariate analysis confirmed FCF and Insall ratio <0.8 as independent predictors of AKP (R. 2. = 0.263). Extension of ≥0.5° predicted AKP with 87% sensitivity. AKP affects 25% of patients following single radius cruciate retaining TKA, resulting in inferior patient-reported outcome measures at 10 years. Sagittal plane positioning and alignment of the femoral component are important determinants of long-term AKP with femoral component extension being a major risk factor

Risk of revision following total knee replacement is relatively high in patients under 55 years of age, but little is reported regarding non-revision outcomes. This study aims to identify predictors of dissatisfaction following TKR in patients younger than 55 years of age. We assessed 177 TKRs (157 consecutive patients) from 2008 to 2013. Data was collected on age, sex, implant, indication, BMI, social deprivation, range of motion, and prior knee surgery in addition to Oxford Knee Score (OKS) and SF-12 score. Postoperative data included knee range of motion, complications, and OKS, SF-12 score and satisfaction measures at one year. Overall, 24.9% of patients (44/177) were unsure or dissatisfied with their TKR. Significant predictors of dissatisfaction on univariable analysis (p<0.05) included: Kellgren-Lawrence grade 1/2 osteoarthritis; indication; poor preoperative OKS; postoperative complications; and poor improvements in OKS and pain component score (PCS) of the SF-12. Odds ratios for dissatisfaction by indication compared to primary OA: OA with previous meniscectomy 2.86; OA in multiply operated knee 2.94; OA with other knee surgery 1.7; OA with BMI>40kgm-2 2; OA post-fracture 3.3; and inflammatory arthropathy 0.23. Multivariable analysis showed poor preoperative OKS, poor improvement in OKS and postoperative stiffness, particularly flexion of <90°, independently predicted dissatisfaction (p<0.005). Patients coming to TKR when under 55 years of age differ from the ‘average’ arthroplasty population, often having complex knee histories and indications for surgery, and an elevated risk of dissatisfaction

Total knee arthroplasty (TKA) is an established and successful operation. However patient satisfaction rates vary from 81 to 89% 1,2,3. Pain following TKA is a significant factor in patient dissatisfaction 1. Many causes for pain following total knee arthroplasty have been identified 4 but rates of unexplained pain vary from 4 to 13.1% 5,6. Recently computerised tomography (CT) has been used to assess the rotational profile of both the tibial and femoral components in painful TKA. We reviewed 57 patients with an unexplained painful following TKA and compared these to a matched control group of 60 patients with TKA. Datum gathered from case notes and radiographs using a prospective database to identify patients. The CT information recorded was limb alignment, tibial component rotation, and femoral component rotation and combined rotation. The two matched cohorts of patients had similar demographics. A significant difference in tibial, femoral and combined component rotation was identified between the groups. The following mean rotations were identified for the painful and control groups respectively. Tibial rotation was 3.46 degrees internal rotation (IR) compared to 2.50 degrees external rotation (ER)(p=0.001). Femoral rotation was 2.30 IR compared to 0.36 ER(p=0.02). Combined rotation was 7.08 IR compared to 2.85 ER(p=0.001). This is the largest study presently in the literature. We have identified significant internal rotation in a patient cohort with unexplained painful TKA when compared to a matched control group. Internal rotation of the tibial component, femoral component and combined rotation was identified as a factor in unexplained pain following TKA

Background. Tranexamic acid (TA) in total knee replacement surgery (TKR) has shown marked reduction in bleeding and blood transfusion. There are little data on TA in revision TKR. From February 2008 all patients having primary or revision TKR received TA 10mg/kg × 2. We whished to evaluate the effect and possible complications of TA. Patients and Methods. 49 patients had revision TKR from January to August 2010. 21 patients (group I) operated before the regular use of TA were compared to 28 patients (group II) receiving TA. The groups were compared according to bleeding, blood transfusion, postoperative complication and type of revision. Revision TKR was compared to 157 primary TKR (94 operated without TA (group III) and 63 who received TA (group IV). Results. Group I: Preoperative Hgl 13.6g/dl (9.2–15.3), reduction in hgl 3.9g/dl (1.0–5.7), bleeding 1040ml (380–2100). 6 patients (28.6%) needed blood transfusion. 7 patients were admitted to cell-saver and were given mean 400 ml blood (150–730). There were 6 revisions from uni-prostheses to TKR and 15 was revision of TKR. There was no difference in bleeding between this to groups (980ml/1030ml). Group II: Preoperative Hgl 14.2g/dl (11.2–18.6), reduction in hgl 3.3g/dl (1.4–8.3), bleeding 490ml (120–1050) (47.1% reduction in bleeding volume (p<0,002)). One patient (3.4%) needed blood transfusion. There was 8 revisions from uni-prostheses to TKR and 21 was revision of TKR. There was no difference in bleeding between this two groups (510ml/570ml). Group III: Preoperative Hgl 14.2g/dl (10.1–17.4), reduction in Hgl 3.5g/dl (1.1–7.7), bleeding 1048ml (50–2230). 15 patients (16%) needed blood transfusion. Group IV: Preoperative Hgl 13.7g/dl (11.6–18.1), reduction in Hgl 2.76g/dl (1.2–4.8) (p=0,014), bleeding 370ml (130–960) (64.5% reduction in volume (p<0,002)). 2 patients (3%) needed blood transfusion. (p=0,004)). There was no statistically significant difference in bleeding between primary and revision TKR (p=0.18). Conclusion. Our results shows that TA reduces bleeding and the need for blood transfusion markedly. The TA groups had no increase in any complications

The primary aim was to assess survival of the opening wedge high tibial osteotomy (HTO) for medial compartment osteoarthritis. The secondary aim was to identify independent predictors of early (before 12 years) conversion to total knee arthroplasty (TKA). During the 18-year period (1994–2011) 111 opening wedge HTO were performed at the study centre. Mean patient age was 45 years (range 18–68) and the majority were male (84%). Mean follow-up was 12 (range 6–21) years. Failure was defined as conversion to TKA. Kaplan-Meier, Cox regression and receiver operating curve (ROC) analyses were performed. Forty (36%) HTO failed at a mean follow-up of 6.3 (range 1–15) years. The five-year survival rate was 84% (95% confidence interval (CI) 82.6–85.4), 10-year rate 65% (95% CI 63.5–66.5) and 15-year rate 55% (95% CI 53.3–56.7). Cox regression analysis identified older age (p<0.001) and female gender (hazard ratio (HR) 2.37, 95% CI 1.06–5.33, p=0.04) as independent predictors of failure. ROC analysis identified a threshold age of 47 years above which the risk of failure increased significantly (area under curve 0.72, 95% CI 0.62–0.81, p<0.001). Cox regression analysis, adjusting for covariates, identified a significantly greater (HR 2.49, 95% CI 1.26–4.91, p=0.01) risk of failure in patients aged 47 years old or more. The risk of early conversion to TKA after an opening wedge HTO is significantly increased in female patients and those older than 47 years old. These risk factors should be considered pre-operatively and discussed with patients when planning surgical intervention for isolated medial compartment osteoarthritis

This study assessed whether patient satisfaction with their hospital stay influences the early outcome of total knee replacement (TKR). During a five year period patients undergoing primary TKR at the study centre had prospectively outcome data recorded (n=2264). Patients with depression (p=0.04) and worse mental wellbeing (p<0.001), according to the short form (SF)-12, were more likely to be dissatisfied with their hospital stay. Decreasing level of satisfaction with their hospital stay was associated with a significantly worse post-operative OKS (p<0.001) and SF-12 score (p<0.001). Multivariable regression analysis confirmed that the patients perceived level of satisfaction with their hospital stay was an independent predictor of change in the OKS (p<0.001) and SF-12 score (p<0.001) after adjusting for confounding variables. Patient satisfaction with their TKR was significantly influenced by their hospital experience, decreasing from 96% in those with an excellent experience to 42% in those with a poor experience. Food, staff/care, and the hospital environment were the most frequent reasons of why patients rated their hospital experience as fair or poor. A patient's perception of their inpatient hospital experience after surgery is an important modifiable predictor of early functional outcome and satisfaction with TKR

Electromagnetic navigation versus conventional Total Knee Arthroplasty: Clinical improvements Optical and electromagnetic (EM) tracking systems are widely used commercially. However in orthopaedic applications optical systems dominate the market. Optical systems suffer from deficiencies due to line of sight. EM trackers are smaller but are affected by metal. The accuracy of the two tracker systems has been seen to be comparable1. Recent advancements in optical navigated TKA have shown improved overall limb alignment, implant placement and reduce outliers when compared to conventional TKA2-4. This study is the first RCT to compare EM and conventional TKA. Two groups of 100 patients underwent TKA using either the EM navigation system or the conventional method. Frontal, sagittal and rotational alignment was analysed from a CT scan. Clinical scores including Oxford Knee Score (OKS) and Knee/Function American Knee Society Score (AKSS) were recorded pre-op, and at 3 and 12 months post-op. 3 month data presented includes 180 patients (n = 90). The 12 months data presented includes 140 (n = 70). The two groups had similar mean mechanical axis alignments (EM 0.31o valgus, conventional 0.15o valgus). The mechanical axis alignment was improved in the EM group with 92% within +/-3o of neutral compared to 84% of the conventional group (p = 0.90). The alignment of the EM group was improved in terms of frontal femoral, frontal tibial, sagittal femoral, sagittal tibial and tibial rotation alignment. However, only the sagittal femoral alignment was significantly improved in the EM group (p = 0.04). Clinically, both TKA groups showed significant improvements in OKS and AKSS scores between both pre-op to 3 month post-op and 3 months to 12 months post-op (p<0.001). The OKS and the AKSS knee score for the EM group was significantly better at 3 months post-op (OXS p = 0.02, AKSS knee p = 0.04). However there was no difference between the groups at 12 months. The mean pre-op range of motion (ROM) for both groups was 105o. This decreased to 102o in the EM group and 99o in the conventional group at 3 months. There was a significant improvement at 12 months post-op, EM = 113o (p = 0.012) and conventional = 112o (p = 0.026). There was no significant difference in ROM between the two groups at 3 or 12 months post-op. Therefore the alignment outcome of the EM TKA group was improved compared to the conventional group. The EM group also showed clinical improvements at 3 months post-op however these were not seen again at 12 months post-op. ROM was seen to decrease at 3 months post-op but then significantly improve by 12 month post-op

Reduced length of stay (LOS) is logistically, economically and physiologically beneficial. Although a high proportion of total joint arthroplasty (TJA) patients are suitable for same day admission (SDA), removable barriers persist in many centres. This study aimed to determine factors limiting SDA and quantify the impact of implementing both SDA and a targeted enhanced recovery programme on length of stay. This single-centre retrospective cohort study collected data on elective TJA patients aged <60. Qualitative service reviews identified opportunities for optimisation. Improvements were implemented in 2017, including: obtaining consent at the pre-assessment clinic and robustly assessing suitability for SDA. A targeted rapid recovery program was implemented in June 2018. Data was collected prior to changes in 2017, and following changes in 2018. 106 of 108 screened patients were eligible for inclusion. There were no significant between-year differences in baseline health characteristics. Significantly greater proportions of 2018 patients were consented at their pre-assessment clinic (56% vs 8.9%, p<0.001) and assessed as suitable for SDA (94% vs 57.1%, p<0.001). Pre-operative LOS was significantly reduced in 2018 for both total hip replacements (median [IQR]: 0[0,0] vs 1[1,1], p<0.001) and total knee replacements (median [IQR]: 0[0,0] vs 0[0,1], p=0.002). The departmental mean LOS improved from 4.7 days to 3.7 days following SDA. This was further shortened to 3.2 days after introduction of the rapid recovery program. When a larger proportion of patients were deemed suitable for SDA, this correlated with reduction of LOS. The department now performs above national standards in both of these parameters

Peri-prosthetic wound infections can complicate total knee arthroplasty (TKA) in 1–1.5% of cases and may require the input of a combined orthopaedic and plastic surgery team. Failure of optimal management can result in periprosthetic joint infection, arthrodesis or in severe cases limb amputation. A retrospective 11-year review of TKA patients was undertaken in a single unit. Data was collected on a proforma and patient demographics were identified by case note analysis. Incidence of periprosthetic wound infections was recorded. A protocol to standardise treatment was subsequently developed following multidisciplinary input. 56 patients over 11 years developed periprosthetic wound infection. 33 patients were available for analysis. The male:female ratio 1:0.7 with a mean age of 70 years (range: 32–88 years). 5 (15%) developed superficial infections, 4 (12%) patients developed cellulitis requiring antibiotics, 14 (42%) with superficial wound dehiscence and 2 (6%) required washout of the prosthesis with long-term antibiotic therapy. 4 (12%) were managed without plastics involvement, one leading to arthrodesis and 4 (12%) had plastic surgical input, with one leading to arthrodesis. The mean time before plastic surgical review after initial suspicion of infection was 13 weeks. The management of periprosthetic wound infections following TKA are variable and can require a multidiscplinary ortho-plastic approach. Early plastic surgical involvement in specific cases may improve outcome. Our proposed management protocol would facilitate in standardising the management of these complex patients